Dual-stop-band filter designed using CRLH transmission line

Since the concept of composite right/left handed (CRLH) transmission line has been proposed, many kinds of structures are presented with different novel features. These structures also have been applied to design microwave components, which have many advantages compared to those conventional components. In this paper, phase characteristics of our partially closed composite right/left-handed (CRLH) transmission line is detailed analyzed, and the experience formula of relationship between shifted phase and structure's length is retrieved based on the simulation results by commercial software of Ansoft HFSS. Then, a novel dual-stop-band filter is proposed where CRLH transmission line is used as a quart wave length open-end stub. Two stop bands with center frequencies of 4 GHz and 6GHz are achieved with total length of 11.34mm, only about 0.15λ 0 at 4GHz.